In the current stainless steel pickling waste water technology, there are many technologies, mainly including neutralization, iron sulfate method, diffusion dialysis - diaphragm electrolysis, oxidation sulfur ammonium iron oxide red, wetland and biological method, high temperature roasting method, thin film evaporation method, such as a variety of ways, by combining the need of practical engineering, to conduct a comprehensive integration from a variety of factors, can have a good technical effect.
1. Briefly describe the overall concept of stainless steel pickling wastewater technology
1.1 Overall features of stainless steel structure
In the current application of some iron and steel technologies, both construction and civil engineering, can show different characteristics, especially the current steel structure of power plants and workshops steel structure design has more overall advantages, can form a unique advantage and characteristics. First, the construction period of steel structure is short, which reduces the investment cost correspondingly. Second, steel structure building fire resistance is high, corrosion resistance is relatively strong; Thirdly, the steel structure has light weight, high strength and large span. Fourth, steel structure construction investment is low, economical; Fifth, the steel structure building is easy to move, recycling pollution-free, good environmental protection; Sixth, steel structure buildings are widely used in workshops, warehouses, restaurants, gymnasiums, large markets, leisure and holiday places, etc., which can play a good practical effect.
2.2 Overall adaptability analysis
Add lye or bauxite to the wastewater to neutralize the acidic wastewater and produce sodium nitrate. The sodium nitrate produced still has a certain solubility, and it is necessary to invest the polyacrylamide flocculant to make the metal ions accumulate and settle. Two-stage treatment was used, and the sediment obtained from the first stage treatment was stirred with a agitator to destroy the balance between the precipitation and ions in the liquid phase, and then it was fully reacted by the neutralization tower, and then the second stage settlement treatment was carried out to get a better result. This method is suitable for treating acid wastewater with high concentration of nitric acid.
2. Analyze the application of stainless steel pickling wastewater treatment technology
2.1 Application of steel structure in atmospheric corrosion environment
From the point of view of the current some technical characteristics, especially in steel structure processing, in order to give full play to the overall characteristics of the steel structure, will be around pickling wastewater integrated use of technology, based on some of the corrosion and corrosive gas cleaning, should be to strengthen the comprehensive management from several aspects, and through the overall use of technology, especially adopting comprehensive technology development and utilization, some of these impurities removal out of attachment in the steel structure, reduce the overall impact of steel structure, crack formation of some of the problems. Therefore, in the comprehensive exploration of the application of steel pickling wastewater technology, it is necessary to comprehensively consider the degree of atmospheric influence of steel structure in buildings and reduce the adverse factors caused by it. Effective treatment of steel structure has become an indispensable link. At the application level of specific technology, we can combine the current advanced equipment and comprehensive modern technical means to absorb the waste acid in the waste liquid into the resin by using the blocking characteristics of ion-exchange resin acid. Other metal salts pass through smoothly, and then use pure water to analyze the resin to recover the acid. Ion exchange resin is used to adsorb strong acid and remove metal salt from the solution, so as to separate free acid and metal ions. In the later stage, wastewater purification equipment can reach zero discharge. Can greatly reduce the cost of wastewater discharge. The application of this technology has a wide range of features, a wide range of equipment, easy to operate; Large handling capacity, high cost performance (relative to membrane acid recovery equipment), can be selected according to the water quality and water quantity requirements, adjustable high to avoid waste of funds, long service life of equipment, low maintenance rate; Regenerated at normal temperature, low energy consumption; The whole set of acid recovery equipment can achieve zero emission and so on. The scope of application is hydrometallurgy, acid making industry, electroplating industry, automobile manufacturing and other mechanical processing industry. Therefore, in the specific application, a systematic technical comprehensive analysis should be formed.
2.2 Sulfuric acid washing liquid iron sulfate treatment
In the treatment technology of ferric sulphate method, the characteristic of this method is that the iron in the waste liquid can be reused. Therefore, researchers attach importance to it and gradually form a more mature practical technology. Better results can be obtained through the concrete application of the sulfuric acid washing liquid iron sulfate treatment, and has been put into production practice. In particular, concentration-Filter-natural crystallization method is also known as iron filings method. Firstly, waste sulfuric acid liquid and iron filings are placed in a reaction tank for full reaction, and then the solution is heated to 100℃ for 2h. After reheating and concentration, natural cooling is conducted to make ferrous sulfate crystal precipitation. The method can be used to recover low, medium and high grade ferrous sulfate from pickling wastewater for industrial, agricultural, pharmaceutical and chemical reagents. It has the advantages of simple and easy operation, less investment, low cost and so on, but it can only recover ferrous sulphate, cannot recover sulphuric acid and has small processing capacity. Product quality is poor, production cycle is long, more suitable for township enterprises small production.